Parents need to know that, compared to today's visually stunning special effects, this show was very low-budget in both props and special effects and may consequently seem silly to modern kids. But beyond that, the series was a metaphor for the upheaval of the 1960s. Behind the storylines of space travel and aliens are important social commentaries on racism, sexism, politics, and the fear that machines might one day rule the world. Taken at face value, though, most of the adventures are pretty innocent and are fine for young tweens and up.